2 resultados para alternative assessment
em Repositório Científico da Universidade de Évora - Portugal
Resumo:
Greenhouse production is a very important activity in the West region of Portugal, with an area of approximately 800 ha where the regular production consists in two crops per year, one in winter-spring and the other in summer-autumn. Many growers are now prepared to better exploit market opportunities, since they know that the big export window opportunity is from June to September, when the production is difficult in other regions of south due to high temperatures. Grower’s use new and more productive varieties, either in soil or hydroponic systems, mostly in unheated greenhouses, naturally ventilated, and equipped with modern fertigation systems. Greenhouse production causes some environmental impacts due to the high use of inputs. Several improvements in technologies and crop practices may contribute to increase the use efficiency of resources, decreasing the negative environmental impacts. Greenhouse vegetable production in Northern EU countries is based on the supply of heating and differs significantly from the production system in the Southern EU countries. In the Northern countries, direct energy inputs, mostly for heating, are predominant while in the South the indirect energy input is also important, mainly associated with fertilizers, plastic cover materials and other auxiliary materials. The main objective of this work was to characterise the greenhouse production systems in the West region of Portugal, in order to evaluate the energetic consumptions (direct and indirect), the GHH emissions, the production costs and the farmer’s income. With this work the mostly important inputs were identified, allowing proposing alternative measures to improve efficiency and sustainability. All the data was obtained by surveys performed directly with growers, previously selected to be representative of the crop practices and greenhouse type of the region. However, more research should be performed in order to develop and to test technologies capable to improve resources use efficiency in greenhouse production.
Resumo:
The damaging of buildings and monuments by biological contamination is a cause of serious concern. Biocides based on chemical toxic compounds have been used to mitigate this problem. However, in the past decade many of the most effective biocides have been banned due to their environmental and health hazards. Therefore, proper remediation actions for microbiologically contaminated historic materials based on environmentally safe solution is of vital importance. Bacillus species are emerging as a promising alternative for built heritage treatment. They produce a great diversity of secondary metabolites with biological activity, well known to possess antagonistic activities against many fungal pathogens. In order to evaluate the antifungal activity of the novel biocides produced in our laboratory by cultures of selected bacterial strains, liquid interaction assays using four biodeteriogenic fungi were achieved, revealing a nearly 100% of inhibitory capacity to fungal proliferation. To confirm their effective safe toxicological properties, in vivo tests using two different biological models were performed. The lyophilized supernatant of the Bacillus culture broth showed no lethality against brine shrimp and also no toxicological effects in Swiss mice through administration of acute dose of 5000 mg/kg by oral gavage. In fact, the bioactive compounds were no lethal at the tested dose unlike Preventol® (commercial biocide) that induced acute toxicity with 10 times minor concentration dose administrated in the same conditions. Therefore, the new bioactive compounds that suppress growth of biodeteriogenic fungi on historical artworks, presenting at the same time no toxicity against other living organisms, constituting an efficient and green safe solution for biodegradation/biodeterioration treatment of Cultural Heritage.